In recent years, cellular communication solutions have transitioned to lower cost uncompensated quartz piezoelectric crystal solutions. However, these low-cost (crystal) cellular solutions cannot inherently be transitioned to a low-cost (uncompensated) crystal solution common to and shared by cellular and Global Positioning System (GPS) systems within a single mobile platform due to the GPS system's stringent maximum frequency slew rate and maximum frequency step change requirements. In prior art embodiments, the GPS system's stringent maximum frequency slew rate and maximum frequency step change requirements generally necessitate incorporation of a Temperature-Compensated-Crystal-Oscillator (also known as a TCXO) to serve as the GPS system's reference oscillator. This TCXO requirement generally applies to both standalone GPS systems and to co-integrated GPS and cellular systems.